1. Field of the Invention
The present invention relates to a method for solderless electrical press-fit contacting of electrically conductive press-fit pins in circuit boards.
2. Description of the Related Art
Press-fit connections for direct contacting of circuit boards are utilized in numerous products. The range of variants extends from individual press-fit pins in onboard computers to edge connectors having up to approx. 100 press-fit pins in control units. With a large number of press-fit pins to be pressed in, requirements become more stringent in terms of the accuracy of the spacings and the orientation of the press-fit pins with respect to one another, the contacting openings in the circuit board, and the positioning of the press-fit pins before and during the press-fitting operation with respect to the contacting openings.
A press-fit pin, or an edge connector having a plurality of press-fit pins, is usually press-fitted into a contacting opening or into a plurality of contacting openings of the circuit board. The contacting opening is often equipped with a press-fit sleeve. The diameter of the press-fit sleeve in the circuit board is as a rule recommended by the supplier of the press-fit pins. The design of the press-fit sleeve depends on the hardness, the geometry, and the utilization of the press-fit pins. As the press-fit pin is press-fitted into the press-fit sleeve, the inner wall of the press-fit sleeve becomes plastically deformed and a frictionally engaged connection is achieved between the press-fit pin and the press-fit sleeve.
The demands in terms of the location and positional accuracy of the press-fit pins with regard to the contacting openings in the context of the press-fitting operation are stringent in order to avoid tilting of the press-fit pins and in order to minimize press-fitting forces. Excessively high press-fitting forces or tilting of the press-fit pins in the press-fitting operation can damage the press-fit sleeve of the contacting opening, or even the circuit board.
Published Japanese patent document JP 2001 024393 discloses that press-fit pins can be press-fitted into a circuit board, in which context the press-fitting operation can be assisted with ultrasound.